1. Technical Field
The present invention relates to light guide plates, and more particularly to a light guide plate used in a liquid crystal display device.
2. Description of Related Art
A liquid crystal display device has characteristics of lightness (in weight), thinness, low power consumption, etc. Liquid crystal display devices are widely used in communication devices, consumer devices, etc. The liquid crystal used in liquid crystal display device itself cannot radiate light, but it can receive light and is capable of manipulating the received light. This means that the liquid crystal display device requires a surface light source in order to display images and data. In a liquid crystal display device, a backlight module is used as the surface light source. The backlight module converts electric energy to light energy, and a light guide plate in the backlight module then converts the supplied light into a uniform surface light for displaying the images and data. The light guide plate is one of the key components of the backlight module. In order to ensure that the surface light has a uniform brightness and color, the light guide plate must be well designed.
A typical backlight module includes a light guide plate and a light source arranged adjacent to one side of the light guide plate. The light guide plate includes a light incidence surface, a light-emitting surface joined with the light incidence surface, and a bottom surface on an opposite side of the light guide plate to the light-emitting surface. A plurality of scattering-dots can be formed on the light-emitting surface. The scattering-dots are generally hemispherical in shape. The light emitted by the light source enters into the light guide plate through the light incidence surface. The light is transferred forward into the light guide plate, and then exits from the light-emitting surface.
The scattering-dots can reflect and refract the light. After reflection and refraction, the light becomes a dispersed, only a small amount of light exits from the direction perpendicular to the light-emitting surface, so the backlight module has low brightness.
What is needed, therefore, is a light guide plate having high brightness.